Elevator cars are conventionally formed to comprise a car box and suspension means, which suspension means comprise hoisting roping and a load-bearing frame, which comprises a lower horizontal beam system, an upper horizontal beam system, and also a vertical beam system of a first side and a vertical beam system of a second side, which beam systems are connected to each other so that they form a closed ring, inside which is an interior comprised in a car box fixed to the beam systems, which interior can receive freight and/or passengers for conveying them in the interior of the elevator car.
Conventionally the car box of an elevator has been essentially fully inside the aforementioned ring. Also known in the art are elevator cars, in which the beams participating in forming the ring structure of the aforementioned load-bearing frame are integrated as a part of the wall structures, roof structures or floor structures bounding the interior of the car box. This type of solution is presented in, among others, publications EP1970341 and WO9933743. Utilizing the solutions, a shallow roof structure for an elevator car can be achieved. The vertical space usage is very efficient, but nevertheless some free space remains unutilized and modification of the elevator car according to site regulations and customer needs is not possible.
The outer surface of the roof of an elevator car is generally formed from plates that are firmly and rigidly supported on the upper horizontal beam system. According to prior art, there is a separate ceiling panel in the elevator cars, below the upper horizontal beam system and the aforementioned plates forming the outer surface. The roof panel can be a single-piece or multi-piece roof panel, and the bottom surface of it forms a planar surface bounding the interior of the car. The roof panel is generally a plate-type structure that is quite thin in terms of its thickness, into which luminaires are sunk. The ceiling panel structure has increased the total thickness of the roof structure by the amount of its own thickness plus possible fastening clearances. Using this type of conventional method in connection with solutions according to prior art produces an unnecessarily thick, heavyweight and technically complex roof entity that is expensive in terms of its manufacturing costs.